Blades of a ceiling fan (2)

ABSTRACT

The blades of a ceiling fan are respectively provided with a top surface, a bottom surface, a front wind-confronting portion and a rear wind-confronting portion respectively formed along an edge of two sides of the top surface and the bottom surface. The front wind-confronting portion and the rear wind-confronting portion wind-confronting portion are respectively formed of a slope having the same inclined direction. No matter if the top surface or the bottom surface faces downward after having the blades fixed with a shaft of a motor, the area of the front wind-confronting portion or the rear wind-confronting portion confronting air is always such minimized that air drag can be lowered. Moreover, with the top surface and the bottom surface attached with different patterns, various pattern combinations can be obtained to diversify the outlook of the ceiling fan.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a ceiling fan, particularly to one whose blades are respectively provided with a front wind-confronting portion and a rear wind-confronting portion that are respectively formed along two sides of the blades so as to lower air drag for promoting power efficiency, with a top surface and a bottom surface interchangeable.

2. Description of the Prior Art

Commonly, as shown in FIG. 1, a conventional ceiling fan 10 is mainly composed of a motor 11 and plural blades 12. The motor 11 is fixed at a certain position, provided with a shaft 111 pivotally positioned at its front for being driven by the motor 11 to rotate. The blades 12 are equidistantly fixed around the shaft 111 to create air flow while being whirled by the shaft 111. As shown in FIGS. 2 and 3, in order to lower air drag while the blades 12 rotate, each of the blades 12 is provided with a wind-confronting portion 121 formed downwards at its two sides respectively; or, as shown in FIG. 4, the wind-confronting portion 121 is formed only at one side of the blades 12 confronting air while the blades 12 rotate. And, the blades 12 are always obliquely fixed with the shaft 111 with a preset angle. Of course, with the wind-confronting portion 121 formed around the blades 12, air drag can be lessened as the area of the wind-confronting portion 121 confronting air can be minimized while rotating the blades 12, so as to promote efficiency of the motor 11.

However, because the blades 12 are obliquely positioned downward, the wind-confronting portions 121 are to comparatively increase their area confronting air, enabling air drag increased. Moreover, the ceiling fan is usually hung in a living room or where is needed to be esthetically ornamented, it has to be comparatively decorative. But the conventional ceiling fan is always made commonplace, it has to be replaced with a new one in case that it cannot match with a decorative environment, posing a further economic burden.

SUMMARY OF THE INVENTION

The object of this invention is to offer blades of a ceiling fan able to interchange their top surface and bottom surface by overturning the blades without downgrading power efficiency.

Each of the blades is respectively provided with a top surface, a bottom surface, a front wind-confronting portion and a rear wind-confronting portion respectively formed obliquely along an edge of two sides of the top surface and the bottom surface. The front wind-confronting portion and the rear wind-confronting portion wind-confronting portion are respectively formed of a slope having the same inclined direction. No matter if the top surface or the bottom surface faces downward after having the blades fixed with a shaft of a motor, the area of the front wind-confronting portion or the rear wind-confronting portion confronting air is always such minimized that air drag can be lowered. Moreover, with the top surface and the bottom surface attached with different patterns, various pattern combinations can be obtained to diversify the outlook of the ceiling fan.

BRIEF DESCRIPTION OF DRAWINGS

This invention is better understood by referring to the accompanying drawings, wherein:

FIG. 1 is a side view of a conventional ceiling fan;

FIG. 2 is a perspective view of a blade of a conventional ceiling fan;

FIG. 3 is a cross-sectional view of a blade of a conventional ceiling fan;

FIG. 4 is a cross-sectional view of another blade of a conventional ceiling fan;

FIG. 5 is a perspective view of a first preferred embodiment of a blade of a ceiling fan in the present invention;

FIG. 6 is a cross-sectional view of the first preferred embodiment of a blade of a ceiling fan in the present invention;

FIG. 7 is a cross-sectional view of the first preferred embodiment of another blade of a ceiling fan in the present invention;

FIG. 8 is a cross-sectional view of the first preferred embodiment of another blade of a ceiling fan in the present invention;

FIG. 9 is a cross-sectional view of the first preferred embodiment of another blade of a ceiling fan in the present invention;

FIG. 10 is a perspective view of a second preferred embodiment of a blade of a ceiling fan in the present invention; and

FIG. 11 is a cross-sectional view of the second preferred embodiment of a blade of a ceiling fan in the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIGS. 5 and 6 show a first preferred embodiment of blades 20 of a ceiling fan in the present invention. Each of the blades 20 is made of a plate, having its one end pivotally fixed with a shaft of a motor (not shown in Figures) so as to rotate thereof. The blade 20 is provided with a top surface 21 and a bottom surface 22, which are attached with different patterns, and a front wind-confronting portion 23 and a rear wind-confronting portion 24 respectively formed obliquely along two lengthwise sides of the top surface 21 and the bottom surface 22. The front wind-confronting portion 23 and the rear wind-confronting portion 24 are respectively formed of a slope inclined in the same direction. Each of the front wind-confronting portion 23 and the rear wind-confronting portion 24 in the embodiment has a flat slope inclining from the top to the bottom. Of course, the front wind-confronting portion 23 and the rear wind-confronting portion 24 can be also formed as a concave or a convex surface, as shown in FIGS. 7 and 8. In addition, in order to prevent a user from being hurt by a sharp edge of the blades 20, a safety arc 25 is created at a boundary between the top surface 21 and the front wind-confronting portion 23, and between the bottom surface 22 and the rear wind-confronting portion 24 respectively.

In order to further understand the structural features, operative techniques and expected effects of the invention, how to use the invention is to be described below.

As shown in FIGS. 5 and 6, when the blades 20 are turned around, the front wind-confronting portion 23 is to confront air with a minimized area for lowering air drag so that the motor can efficiently work to provide powerful rotation. If the top surface 21 and the bottom surface 22 are interchanged by overturning the blade 20, the rear wind-confronting portion 24 can still confront air with a minimized area without downgrading efficiency. Thus, with the diverse patterns attached on the top surface 21 and the bottom surface 22, a variety of the pattern combinations can be achieved to diversify the outlook of the ceiling fan.

As shown in FIGS. 10 and 11, a second preferred embodiment of blades of a ceiling fan in the present invention has the same components as the first one does, except that the front wind-confronting portion 23 and the rear wind-confronting portion 24 are gradually widened toward one side of the blades 20 opposite to that pivotally fixed with the shaft of the motor, so that a greater front wind-confronting portion 23 and rear wind-confronting portion 24 are formed at the outer portion of the blades 20 to further lessen air drag and promote the motor's efficiency.

The invention has the following advantages as can be seen from the foresaid description.

1. With the front wind-confronting portion 23 formed on the top surface 21 and the rear wind-confronting portion 24 formed on the bottom surface 22, air drag can be minimized to promote efficiency of the ceiling fan.

2. With the different patterns attached on the top surface 21 and the bottom surface 22 of the blades 20, a variety of the pattern combinations can be achieved to diversify the outlook of the ceiling fan.

While the preferred embodiment of the invention has been described above, it will be recognized and understood that various modifications may be made therein and the appended claims are intended to cover all such modifications that may fall within the spirit and scope of the invention. 

1. Blades of a ceiling fan, each of said blades made of a plate and having its one short side pivotally fixed with a shaft of a motor so as to rotate thereof and comprising: a top surface and a bottom surface which are formed flat, a front wind-confronting portion formed obliquely along a front and a rear side of said top surface, a rear wind-confronting portion formed obliquely along a front and a rear side of said bottom surface, said front wind-confronting portion and said rear wind-confronting portion being shaped as a slope with a same inclined direction.
 2. The blades of a ceiling fan as claimed in claim 1, wherein said front wind-confronting portion and said rear wind-confronting portion are respectively formed along two lengthwise sides of said top surface and said bottom surface.
 3. The blades of a ceiling fan as claimed in claim 1, wherein said front wind-confronting portion and said rear wind-confronting portion are respectively formed along two lengthwise sides of said top surface and said bottom surface, gradually widened toward a short side of said blades opposite to that pivotally fixed with a shaft of a motor.
 4. The blades of a ceiling fan as claimed in claim 1, wherein said slopes of said front wind-confronting portion and said rear wind-confronting portion are shaped the same.
 5. The blades of a ceiling fan as claimed in claim 1, wherein said slopes of said front wind-confronting portion and said rear wind-confronting portion are formed flat.
 6. The blades of a ceiling fan as claimed in claim 1, wherein said slopes of said front wind-confronting portion and said rear wind-confronting portion are formed concave.
 7. The blades of a ceiling fan as claimed in claim 1, wherein said slopes of said front wind-confronting portion and said rear wind-confronting portion are formed convex.
 8. The blades of a ceiling fan as claimed in claim 1, wherein said top surface and said bottom surface are decorated with different patterns.
 9. The blades of a ceiling fan as claimed in claim 1, wherein a safety arc 25 is formed at a boundary between said top surface and said front wind-confronting portion, and between said bottom surface and said rear wind-confronting portion respectively. 